Revolving door speed control device



March 7, 1967 A. E. S HECKELLS REVOLVII JG DOOR SPEED CONTROL DEVICE Filed July 15, 1964 3 Sheets-Sheet 1 INVENTOR AMUEL E. SHECKELLS W A'ITOR M r 7, 1967 I A. E. SHECKELLS 3,307,660

REVOLVING DOOR SPEED CONTROL DEVICE Filed July 15, 1964 5 Sheets-Sheet 2 4| INVENTOR.

1 40b AMUEL E. SHECKELLS FIG. 5

March 7, 19.67 A. E. SHECKELLS 3,307,660

REVOLVING DOOR SPEED CONTROL DEVICE Filed July 15, 1964 5 Sheets-$heet 5 H66 HQ? v INVENTOR. AMUEL E SHECKELLS A T'I OR If Y United States Patent 3 307 660 REVOLVING noon *srEED CONTROL DEVICE Amuel E. Sheckells, Evansville, Ind., assignor to International Steel Company, Evansville, Ind., a corporation of Indiana Filed July 15, 1964, Ser. No. 382,791 6 Claims. (Cl. 188-185) This invention relates to a speed control mechanism and more particularly to a speed control mechanism for revolving doors.

Heretofore many types of speed control devices have been devised for limiting the speed of rotation of revolv' ing doors. These devices usually include a gear train operatively connected between the shaft of the revolving door and a centrifugal brake mechanism whereby, upon rotation of the revolving door beyond a certain speed, the centrifugal brake mechanism is actuated.

While these speed control devices have been satisfac' tory for their intended purposes, they have been open to certain objections. One such objection is the bulkiness of the mechanism caused by the design of the gear train for operating the centrifugal brake assembly. Because of the bulkiness the speed control mechanism had to be designed specifically for installation in either the overhead or floor type revolving door installation.

Another disadvatage in hitherto employed revolving door speed control devices was the constant maintenance required in adjusting cleaning and lubricating the mechanism to prevent the accumulation of moisture, rust, etc., which causes the braking assembly to grab with the re sultant chattering of the door when operated.

After considerable research and experimentation, the revolving door speed control mechanism of the present invention has been devised to overcome the aforementioned disadvantages in hitherto employed speed control devices. The speed control mechanism of the present invention comprises, essentially, a gear train positioned within a housing and operatively connected between a shaft of a revolving door and a centrifugal brake assembly; the housing, gear train and brake mechanism being constructed and arranged to form a low-profile assembly, whereby the control mechanism can be selectively mounted in either an overhead or floor type revolving door in stallation. The housing of the speed control mechanism is also adapted to receive a volume of oil which .not only provides continuous lubrication of the mechanism but also coacts with the braking assembly to provide a smooth and dependable braking action.

When using the speed control mechanism of the pres ent invention in an overhead installation, the housing is adapted to be provided with either shock absorbers, or wheels in the case of revolving doors requiring a roll-aside feature wherein the door wings and control mechanism are moved to one side to provide a larger access opening in the doorway, the roll-aside assembly being further provided with novel detent means to release the control mech anism when being moved to One side.

An object of the invention is to provide an improved low-profile speed control mechanism adapted to be selec' tively mounted in either an overhead or floor type revolv' ing door installation.

Another object of the invention is to provide an improved speed control mechanism, including a centrifugal brake assembly where in a film of oil coacts with the brake assembly to provide a smooth braking action.

Still another object of the invention is to provide an improved speed control mechanism having a gear train operatively connected between the shaft of a revolving door and a centrifugal brake assembly, the gear train being constructed and arranged to have a vgear ratio of 100 to l.

3,307,660 Patented Mar. 7, 1967 ice Yet still another object of the invention is to provide an improved speed control mechanism including a housing containing a gear train and a centrifugal brake assembly, the housing being adapted to be selectively provided with shock absorbers or wheels when mounted in an overhead revolving door installation.

A further object of the invention is to provide an improved speed control mechanism, characterized by its compactness and ruggedness in construction and which is not likely to get out of order even after long and continued use.

With these and other objects in view, which may be incident to my improvements, the invention consists in the parts and combinations to be hereinafter set forth and claimed, with the understanding that the several necessary elements comprising my invention, may be varied in construction, proportions and arrangements, without departing from the spirit and scope of the appended claims.

In order to make my invention more clearly understood, I have shown in the accompanying drawings means for carrying the same into practical effect, without limiting the improvements in their useful application to the particular constructions which, for the purpose of explanation, have been made the subject of illustration.

In the drawings:

FIGURE 1 is a top plan View of the improved speed control mechanism mounted in a floor type revolving door installation;

FIG. 2 is a sectional view of the mechanism taken along line 22 of FIG. 1; 7

FIG. 3 is a plan view of the gear train employed in the speed control mechanism taken along line 33 of FIG. 2;

FIG. 4 is an enlarged sectional view of the centrifugal brake assembly employed in the speed control mechanism of the present invention;

FIG. 5 is a view of the centrifugal brake assembly taken along line 5-5 of P164;

FIGS. 6 and 7 are fragmentary plan views showing modifications of the mechanisms adapted for mounting in overhead type revolving door installations;

FIG. 8 is an enlarged sectional view taken along line 8-8 of FIG. 6; and

FIG. 9 is a view taken along line 9-9 of FIG. 7.

Referring to the drawings, and more particularly to FIGS. 1 and 2, the speed control mechanism of the present invention comprises an integral, cast housing 1 enclosing a gear train 2 operatively connected between a revolving door shaft 3 and a centrifugal brake assembly 4. The assembly shown in FIGS. 1 and 2 is adapted for mounting in a floor-type revolving door installation, wherein housing 1 is secured to a base plate 5 by means of suitable bolts 6 threaded into bore 6a formed in the housing and extending transversely through brackets 7 11. The upper end of the stub shaft is provided with a grooved bore 10a adapted to receive the reduced, splined end portion 3a of the door shaft 3. A dust cap 12 is mounted between the upper end of the stub shaft and the reduced end portion of the door shaft for covering a resilient seal 13 carried by a cylindrical seal retainer 14 which is formed with a flange 14a at its lower end through which suitable screws 15 extend to secure the retainer to a plate 16 which is coextensive with the floor of the installation. A rectangular plate 17 is positioned below the floor plate and is secured to cover plate 8 by means of suitable screws 18, the rectangular plate being provided with an aperture in which the bearing 11 and a resilient seal 19 are mounted for engaging the stub shaft which extends therethrough.

As will be seen in FIGS. 2 and 3, the gear train for the mechanism comprises a main gear 20 having a hub portion 20a keyed to stub shaft as at 21. The main gear is rotatably mounted within the housing by means of an anti-friction bearing 22, said main gear being adapted to mesh with a pinion 23 carried by shaft 24 which is rotatably mounted within the housing by means of bearings 25. An intermediate gear 26 is also carried by shaft 24 and meshes with a pinion 27 carried by a second shaft 28 which is rotatably mounted within the housing by means of bearings 29. A second intermediate gear 30 is carried by shaft 28 and meshes with a third pinion 31 secured to the centrifugal brake assembly shaft 32 which is rotatably mounted within the housing by means of bearing 33. The gear train is designed to have a gear ratio of 100 to 1 to thereby increase the sensitivity of the centrifugal brake assembly in response to rotation of the revolving door shaft, to be described more fully hereinafter. While gears 30 and 31 have been shown and described as pinion gears, they are preferably helical gears to keep the noise level of the speed control at the higher operating speeds as low as possible.

Referring to FIGS. 4 and 5, the centrifugal brake assembly comprises a housing 34 positioned within the speed control mechanism housing 1 by means of dowel pins 35 (FIG. 1) and secured therein by suitable bolts 36. The brake housing is provided with a hub portion 34a through which the shaft 32 extends and is rotatably mounted therein by means of bearing 37. A worm-like member 38 which functions as an oil pump of the screwtype, to be described more fully hereinafter, is carried by shaft 32 on the lower end portion thereof and is positioned within the hub portion 34a, the upper end portion of shaft 32 being provided with a rotor 39 keyed to the shaft as at 40. The rotor is provided with a tapped bore 40a disposed in the medial portion thereof, the rotor also being provided with a pair of parallel bores 40b extending through the rotor and positioned on opposite sides of tapped bore 40a (FIG. 5). Each of the bores 40b is provided with a pair of oppositely extending guide pins 41 which are adapted to slidably receive a brake shoe 42, each brake shoe being held on its respective pair of guide pins by means of a bolt 43 positioned within a recess 42a formed in the brake shoe and threaded into the tapped bore 40a, the brake shoes being urged radially inwardly by means of coil springs 44 positioned between the bolt heads 43a and a shoulder 42b formed on the inner end of the recess 42a, Thus, it will be readily understood that the biasing force of springs 44 urging brake shoes 42 inwardly toward the rotor can be varied by moving bolts 43 inwardly or outwardly relative to the rotor, the bolts being held in adjusted position by means of suitable set screws 45 extending normal to the bolts (FIG. 4). To complete the brake assembly the outer ends of the brake shoes are provided with arcuate shaped brake bands 420 which are adapted to engage the inner periph eral wall 34a of the brake housing during the braking action.

The operation of the centrifugal brake assembly will be readily apparent to those skilled in the art; thus the centrifugal force produced by rotation of shaft 32 causes the brake shoes 42 to slide radially outwardly whereby the brake bands 42c engage the peripheral wall of the brake housing to thereby control the speed of the mechanism. As the brake shoes move radially outwardly springs 44 are compressed so that when shaft 32 stops rotating the springs expand, thereby biasing the brake shoes inwardly to their normal position as shown in FIGS. 4 and 5.

As noted hereinabove, one of the disadvantages experienced in hitherto employed speed control devices was the chattering of the door caused by the grabbing of the brake bands against the wall of the brake housing when the door was operated. This objectionable feature is due partly to the design of the brake assemblies used in the prior art speed control devices which normally consist of a horizontal rotating disc having an upwardly extending pin attached thereto and to which a brake shoe assembly is pivotally connected. As the horizontal disc is rotated the brake shoe assembly is thrown radially outwardly by centrifugal force and pivots about the upstanding pin into engagement with the wall of the brake housing. The 'brake shoe assembly thus always approaches engagement with the wall at an angle and heretofore a locking or binding effect has been realized when the shoes engage with the brake housing wall. This is caused by the fact that the angle between the brake band, the drive pin and the center of rotation is not constant and thus uneven forces are exerted on the wall of the brake housing by the brake shoes. This objection has been overcome by the speed control device of the present invention by omitting the pivot angle and providing a brake shoe construction wherein braking is due to centrifugal force only and not to locking mechanical lever brake mechanisms.

In a preferred construction of the invention, the smooth operation of the control is enhanced by providing the housing 1 with a volume of oil or lubricating fluid sufficicnt to maintain the screw pump 38 submerged therein, the oil level being shown in dashed lines and so designated in FIGS. 2 and 4. As shaft 32 rotates, screw pump 38, which is secured to the shaft, performs as a screw-type pump and supplies a small volume of oil to the brake housing 34. As the oil is supplied to the brake housing it impinges upon rotor 39 and brake shoes 42 with the result that the centrifugal force of the rotating mem- 'bers causes the oil to be flung outwardly, thereby forming a thin film of oil on the brake housing wall 34a, the floor of the brake housing being provided with a port 34b to allow the oil to return to housing 1. By this construction and arrangement, a lubricated surface is provided between the brake bands and brake housing wall which results in a smooth braking action to thereby preclude the grabbing of the brake bands against the wall.

Reference being had to FIG. 2, it will be noted that main gear 20, pinion 23, and centrifugal brake assembly 4 are positioned in substantially the same horizontal plane, and intermediate gear 26, pinion 27 and gears 30 and 31 are positioned in substantially another horizontal plane which is spaced below and closely adjacent to the first mentioned horizontal plane. By positioning these various elements in closely adjacent horizontal planes, a low-profile speed control device is produced which can be easily modified for either floor or overhead-type door installations.

To modify the floor-type speed control device shown in FIGS. 1 and 2 for use in an overhead-type installation, illustrated in FIGS. 6 and 7, bolts 6 are replaced by rubber shock absorbers 46 carried by threaded stems 47 which extend between and are secured within the housing bores 6a, and the beam (not shown) of the door frame construction. These shock absorbers as indicated from FIGS. 6, l and 2 are mounted in the same horizontal plane as the housing 1 to enable the control to be installed in a relatively thin header over the door. The shock absorbers besides dampening noise from the control also aid in aligning the revolving door shaft with the opening in main gear 20 during installation. In the case of an overhead installation having a roll-aside feature wherein the door wings and control device are moved to one side to provide a larger access opening in the doorway, wheels 48 (FIG. 7) are provided which are rotatably mounted on stub shafts 49 mounted within the bores 6a. In this arrangement the wheels 48 are adapted to roll on tracks 50 (FIG. 9) of angle beams 51 of the door frame construction.

The roll-aside type overhead installation is also provided with detent means 52 (FIG. 6) for holding the speed control mechanism in place while the revolving door is.

in its normal operating position. As will be seen in FIG. 9 the detent means comprises a resilient plunger 53 provided with a slot 53a through which'a threaded pin 54 extends, the ends of said pin being secured within opposite walls of a recess 55 formed in the bottom wall of the housing 1. A spring 56 is positioned within recess 55 for biasing the convex end 53b of the plunger into a concave recess formed in the surface of the beam 51.

For purposes of clarity, the shock absorbers 46 and wheels 48 are shown in FIGS. 6 and 7, respectively, as being mounted on one end of the speed control housing; however, it will be understood that the opposite end of the housing will be provided with a duplicate pair of shock absorbers or wheels depending upon the type of overhead installation being employed.

Further modification of the speed control device for use in the overhead-type revolving door installation is illustrated in FIG. 8, wherein the upper end of the door shaft 3 extends through an opening 1a formed in the bottom wall of housing 1, the end of the door shaft being threadably secured to a key member 57 which is splined to the hub 21 of main gear 20. The main gear is rotatably mounted within the housing by means of anti-friction bearing 58 and a suitable sealing member 59, biased against the shaft, is positioned within the opening 1a to prevent leakage of oil from the housing.

In the operation of the speed control device, whethe it be the floor-type as ShOWn in FIGS. 1 and 2, or the overhead-type as illustrated in FIGS. 6, 7 and 8, when the revolving door shaft 3 is rotated, the main gear 20 is rotated to thereby cause rotation of the various gears in the gear train 2 which actuates the centrifugal brake mechanism 4, as described hereinabove, whereby the speed of rotation of. the revolving door is governed.

It will also be readily apparent that the volume of oil contained within the housing not only provides a smooth braking action for the assembly but it also provides a constant lubrication for the various moving parts of the device. Furthermore, by providing the gear train with a ratio of 100 to l, the speed control device is readily adaptable for motor drive revolving door installations wherein the motor and clutch assembly can be connected directly to the high speed pinion gear 31 and shaft 32 without requiring the use of bulky and space-consuming reduction gear assemblies.

While I have shown and described the preferred embodiment of my invention, I wish it to be understood that I do not confine myself to the precise details of construction, herein set forth by way of illustration, as it is apparent that many changes and variations may be made therein, by those skilled in the art, without departing from the spirit of the invention, or exceeding the scope of the appended claims.

What is claimed is:

1. A revolving door speed control device of the character described, comprising a housing, a main gear rotatably mounted within said housing, said main gear adapted for connection to a revolving door shaft, a centrifugal brake assembly including braking surface means positioned within the housing, gear train means rotatably mounted within the housing, said gear train means being operatively connected between the main gear and the centrifugal brake assembly, whereby upon rotation of the revolving door, lubricating fluid bath means within said housing, and lubricating fluid pump means operatively connected to the lubricating fluid bath means and said centrifugal brake assembly and operative upon rotation of said centrifugal brake assembly for directing a volume of lubricating fluid onto said braking surface means in said brake assembly upon actuation thereof.

2. A revolving door speed control device of the character described comprising, a main housing, a main gear rotatably mounted within said main housing, said main gear adapted to be secured to the revolving door shaft, a centrifugal brake assembly including a second housing mounted within the main housing, a rotatable shaft extending through said second housing, gear train means rotatably mounted within the main housing, said gear train means being operatively connected between said main gear and one end of said shaft, a rotor secured to the opposite end of said shaft, a pair of diametrically opposed bolts secured to said rotor and extending radially outwardly therefrom, a brake shoe slidably mounted on each bolt, brake band means connected to the brake shoes, a volume of lubricating fluid contained in said main housing, pump means connected to said shaft, said main gear, gear train means, and centrifugal brake assembly all being positioned within said housing in spaced parallel, closely adjacent horizontal planes to thereby form a low-profile speed control device, whereby upon rotation of the revolving door shaft the resultant centrifugal force causes the brake shoes to move radially outwardly from the rotor causing the brake bands to engage the wall of the second housing, and said pump means being responsive to rotation of the brake assembly shaft for coating the wall of the second housing with a thin film of lubricating fluid to thereby provide a smooth braking action when said brake bands engage the wall.

3. A revolving door speed control device for the shaft of a revolving door comprising, a main housing, a first gear rotatably mounted within said housing, said first gear adapted for connection to the revolving door shaft, a centrifugal brake assembly including braking surface means positioned within and in communication with the main housing, gear train means rotatably mounted within the main housing and operatively connected between the first gear and said centrifugal brake assembly, and lubricating fluid in said main housing being at all times in contact with said braking surface means and said gear train means upon rotation of the revolving door shaft, whereby upon rotation of the shaft the centrifugal brake assembly is actuated to smoothly govern the speed of rotation of the revolving door.

4. A revolving door speed control device according to claim 3, wherein said first gear, gear train means and centrifugal brake assembly are all positioned within said main housing in spaced, parallel, closely adjacent horizontal planes to thereby form a low-profile speed control device adapted for selective installation in either an overhead or floor-type revolving door installation.

5. A revolving door speed control device of the character described comprising, a housing, a main gear rotatably mounted within said housing, said main gear adapted for connection to a revolving door shaft, a centrifugal brake assembly positioned within the housing, gear train means rotatably mounted within the housing, said gear train means operatively connected between the main gear and the centrifugal brake assembly, whereby upon rotation of the revolving door shaft the centrifugal brake assembly is actuated to thereby govern the speed of rotation of the revolving door, said main gear, gear train means and centrifugal brake assembly all being positioned within said housing in spaced parallel, closely adjacent horizontal planes to thereby form a low-profile speed control device adapted for selective installation in either an overhead or floor-type revolving door installation, and shock absorber means connected at substantially right angles to the housing in a horizontal plane bounded by the vertical dimensions of said housing for resiliently supporting the speed control device between the beams of an overhead type revolving door installation to dampen the noise therefrom and aid in aligning the revolving door shaft with said main gear.

6. A revolving door speed control device of the character described comprising, a housing, a main gear rotatably mounted within said housing, said main gear adapted for connection to a revolving door shaft, a centrifugal brake assembly positioned within the housing, gear train means rotatably mounted within the housing, said gear train means operatively connected between the main gear and the centrifugal brake assembly, whereby upon rotation of the revolving door shaft the centrifugal brake assembly is actuated to thereby govern the speed of rotation of the revolving door, said main gear, gear train means and centrifugal brake assembly all being positioned Within said housing in spaced parallel, closely adjacent horizontal planes to thereby form a low-profile speed control device adapted for selective installation in either an overhead or floor-type revolving door installation, wheels connected to the housing, said wheels being adapted to travel in track means carried by the beams in an overheadtype revolving door installation, and spring detent means connected transversely of said housing and in the same References Cited by the Examiner UNITED STATES PATENTS 2,128,531 8/1938 Hagenbook 49-43 2,566,036 8/1951 Shafi 188185 X 2,976,955 3/1961 Huber 188-484 X 3,262,524 7/1966 Haslehurst 18882.9

DUANE A. REGER, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N6. 3,307,660 March 7, 1967 Amuel E. Sheckell It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line 64, after "door" insert shaft the centrifugal brake assembly is actuated to thereby govern the speed of rotation of the revolving door Signed and sealed this 26th day of August 1969.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer 

1. A REVOLVING DOOR SPEED CONTROL DEVICE OF THE CHARACTER DESCRIBED, COMPRISING A HOUSING, A MAIN GEAR TOTATABLY MOUNTED WITHIN SAID HOUSING, SAID MAIN GEAR ADAPTED FOR CONNECTION TO A REVOLVING DOOR SHAFT, A CENTRIFUGAL BRAKE ASSEMBLY INCLUDING BRAKING SURFACE MEANS POSITIONED WITHIN THE HOUSING, GEAR TRAIN MEANS ROTATABLY MOUNTED WITHIN THE HOUSING, SAID GEAR TRAIN MEANS BEING OPERATIVELY CONNECTED BETWEEN THE MAIN GEAR AND THE CENTRIFUGAL BRAKE ASSEMBLY, WHEREBY UPON ROTATION OF THE REVOLVING DOOR, LUBRICATING FLUID BATH MEANS WITHIN SAID HOUSING, AND LUBRICATING FLUID PUMP MEANS OPERATIVELY CONNECTED TO THE LUBRICATING FLUID BATH MEANS AND SAID CENTRIFUGAL BRAKE ASSEMBLY AND OPERATIVE UPON ROTATION OF SAID CENTRIFUGAL BRAKE ASSEMBLY FOR DIRECTING A VOLUME OF LUBRICATING FLUID ONTO SAID BRAKING SURFACE MEANS IN SAID BRAKE ASSEMBLY UPON ACTUATION THEREOF. 